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APFS + TRIM slows down some SSDs
- Thread starter Chrizx74
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Apple guru doesn't know what he's talking about.
You don't absolutely need TRIM.
It helps, but the drive will probably do fine without it.
I've been booting and running my 2012 Mac Mini from a USB3 SSD for FIVE YEARS without TRIM.
It runs as well today as when I first turned it on.
What follows is specifically for user allen.m.cohen:
You have a Samsung SSD mounted in a MacBook?
Running High Sierra with TRIM currently disabled?
If so, I have something I'd like you to try and get back to us with the results.
Trying this will harm or change NOTHING in your current setup.
It will take less than a minute of your time.
(I don't have the capability to do this, this is why I'm asking for someone else who DOES have the capability to try it to post and get back to us.)
Here's what you need to do:
1. Open Disk Utility
2. Choose the "Repair Disk" option
3. Now, click the disclosure arrow to see the log of what DU is doing
4. It will give you a progress report as it does its thing
5. Do you see the line in there "Trimming unused blocks"?
THIS is the critical piece of info I'm looking for.
What this indicates that it's possible to run without TRIM (for faster boot speeds), but STILL BE ABLE TO "TRIM THE DRIVE" using Disk Utility at reasonable intervals...
It helps, but the drive will probably do fine without it.
I've been booting and running my 2012 Mac Mini from a USB3 SSD for FIVE YEARS without TRIM.
It runs as well today as when I first turned it on.
What follows is specifically for user allen.m.cohen:
You have a Samsung SSD mounted in a MacBook?
Running High Sierra with TRIM currently disabled?
If so, I have something I'd like you to try and get back to us with the results.
Trying this will harm or change NOTHING in your current setup.
It will take less than a minute of your time.
(I don't have the capability to do this, this is why I'm asking for someone else who DOES have the capability to try it to post and get back to us.)
Here's what you need to do:
1. Open Disk Utility
2. Choose the "Repair Disk" option
3. Now, click the disclosure arrow to see the log of what DU is doing
4. It will give you a progress report as it does its thing
5. Do you see the line in there "Trimming unused blocks"?
THIS is the critical piece of info I'm looking for.
What this indicates that it's possible to run without TRIM (for faster boot speeds), but STILL BE ABLE TO "TRIM THE DRIVE" using Disk Utility at reasonable intervals...
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It doesn't matter what you did, so in your own words please tell why you think TRIM is useless on SSD and it will "probably do fine without it". Do you at least have an idea of what TRIM is used for? Also, SSD over USB is a completely different story. It's even possible that the USB bridge controller is trimming the drive without your knowledge.
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If you want to regain your original speed you only need to backup your system to time machine and restore it from recovery to the SSD. I did that and boot time changed from 47 secs to 27 secs. I tried on different machines, same result. TRIM enabled of course.
TRIM is not available via USB.
To make TRIM work, it require the OS to co-operate. If the OS report TRIM not avail, it's impossible to TRIM a SSD.
Ok, I'm adding system details here, but I'm not convinced the issue is SSD make/model related. I'll explain why below:
MacBook Pro 13" Mid 2010. 4GB RAM with a Sandisk Ultra II 120GB SSD. Tried both High Sierra 10.13.3 and 10.13.4. Also tried with 10.13.3 previously clean installed on a different machine on a Kingston SSDnow 300 V 60GB SSD. Also tried with a clean install of High Sierra 10.13.4 on a Kingston SSDnow 200 V+.
Cold boot times started off at 1:20 (m:ss) and pretty much stayed consistently there across all variations with a couple of exceptions. That's from pressing the power button to sitting at a usable desktop after inputting the logon password. When the machine booted slowly, app launch times were extended beyond reasonable/tolerable levels too - e.g. 1 minute to launch the App Store, 12 seconds to launch Mail with no accounts set up. 10 seconds to launch Photos with no photos in the library.
I didn't try all combinations of all variables but stopped when performance was acceptable.
My observations can be summarised as follows:
The first clean install of 10.13.4 on the Kingston 200 V reduced boot times to 32secs. That's with trimforce disabled (the default). After enabling trimforce, boot times jumped up to 1 minute.
By now I'd already tried trimforce on and off on the original Sandisk Ultra II with 10.13.4. This was an in place upgrade from 10.13.3 which in turn was an in place upgrade from something earlier by someone else. The FS had already been updated to APFS by the original OS update.
Something made me carry out a PRAM reset. The same install with the Sandisk now cold booted in 39 seconds. That's with Trimforce enabled. App Store launched in 11 secs.
So I went for a clean install of 10.13.4 on the Sandisk. Cold boots now take 32 secs (incl inputting the password). App Store launches in 4 secs. Photos in 2secs. Everything else feel nice and snappy as it ought to.
I would add that a) I created an APFS volume for the clean install using Disk Utility. b) Those timings are with trimforce enabled.
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I only became aware of the problem when I had a 240GB WD Green installed in a Late-2015 21" Retina iMac. I was so disappointed as merely sending the unit to be opened and the HDD replaced with the SSD was already a mission in itself. I restored from a TM backup. The overall performance seemed to be good but the write speed was down to about 50MB/s (Black Magic) while at the same time the read speed was close on 500.
I decided to install from scratch, using the latest HS download from the AppStore three days ago, 10.13.6, and so there is no case of patching up. Same result. I then checked my Late 2015 27" iMac and my Mid-2014 MacBook Pro. While I cannot remember what the results were with Sierra, the figures I now get on HS just seem odd.
I get the idea that the slow write speeds have nothing to do with TRIM or a failing SSD, but rather that HS does not provide accurate information to the Black Magic (latest version on all my Macs) app.
I decided to install from scratch, using the latest HS download from the AppStore three days ago, 10.13.6, and so there is no case of patching up. Same result. I then checked my Late 2015 27" iMac and my Mid-2014 MacBook Pro. While I cannot remember what the results were with Sierra, the figures I now get on HS just seem odd.
I get the idea that the slow write speeds have nothing to do with TRIM or a failing SSD, but rather that HS does not provide accurate information to the Black Magic (latest version on all my Macs) app.
I can confirm that simply running a restore from TM in recovery mode solved the problem completely. Trim still enabled. Latest OS (10.13.6)